1. Field of the Invention
The present invention relates to a power transmission apparatus for a wind generator.
2. Description of Related Art
As well known to those skilled in the art, wind generators generate electricity using the power of an apparatus rotor, which is rotated by wind. Generally, a wind generator is configured such that a tower is installed at a designated height above the ground and an apparatus rotor having a plurality of rotating blades and a generator are connected by a main shaft above the tower so as to transmit the rotary power of the apparatus rotor to the generator through the main shaft.
In the apparatus rotor, the plurality of rotating blades is fixed along the circumferential surface of a rotor hub formed at the front end of the main shaft by blade fixtures. The blade fixtures use a conventional method, such as bolt fastening.
FIG. 6 is a sectional view illustrating the internal structure of a conventional wind generator. As shown in FIG. 6, the generator 4 includes a stator 411 and a rotor 412, which are spaced from each other by a designated interval, and the main shaft 2, both ends of which are supported by a front bearing 5 and a rear bearing 6, is divided into a turbine shaft 2a and a generator shaft 2b, which are connected by a flange joint 2c. Further, the rotor 412 is connected to the generator shaft 2b and is rotated together with the rotation of the generator shaft 2, and generates electricity due to the electrical action with the stator 411.
Now, the connection structure of the stator 411 and the rotor 412 to the generator shaft 2b will be described in more detail. Both ends of the generator shaft 2b are supported by bearings 413, a stator housing 411a is connected to the bearings 413, and a rotor body 412a is connected directly to the generator shaft 2b. 
In the conventional wind generator, when the stator 411 and the rotor 412 are connected to the generator shaft 2b, the assembly of the stator housing 411a to the electric bearings 413 and the connection of the rotor body 412a directly to the generator shaft 2b are separately carried out, thus causing troublesome and inconvenience in assembly and deteriorating efficiency in assembly. Now, the connection structure of the stator 411 and the rotor 412 to the generator shaft 2b will be described in more detail. Both ends of the generator shaft 2b are supported by electric bearings 413, and a stator housing 411a is connected to the electric hearings 413, and a rotor body 412a is connected directly to the generator shaft 2b. In the conventional wind turbine, when the stator 411 and the rotor 412 are connected to the generator shaft 2b, the assembly of the stator housing 411a to the electric bearing 413 and the connection of the rotor body 412a directly to the generator shaft 2b are separately carried out, thus causing troublesome and inconvenience in assembly and deteriorating efficiently in assembly.
The main shaft 2 is divided into the turbine shaft 2a and the generator shaft 2b, which are connected by the flange joint 2c, as described above, and thus causes a loss in transmission of rotational torque.
Generally, in a generator or a motor, over-current flows in wires inside a stator due to natural degradation, physical defects, or overload, and the insulation between the wires in the stator is destroyed by the repetition of the above over-current flow, thus causing a short. In this case, counter torque due to over-current is produced in the generator.
The conventional wind generator is not provided with any unit for preventing the above counter torque caused by the short, thus having many defects, such as damage to the wind generator, shortening of the life span of the wind generator, and a difficulty in maintenance and repair of the wind generator.
Further, in case that the misalignment and the tilting of the main shaft are generated, the conventional wind generator does not have a self-aligning function of the main shaft, and thus causes inaccuracy in power transmission and operation due to the misalignment and the tilting of the main shaft.